Since
the development of supramolecular chemistry, synthetic macrocycles have also
played an inevitable role in constructing the host-guest system. Among pillar[n]arenes,
in short pillarenes, a decade-old younger member in the supramolecular family,
after reported by Ogoshi et al. in 2008, has gained considerable attention. Due to the
straightforward preparation methods, tunable cavity size, and symmetrical architecture
makes it an ideal candidate in the supramolecular family. With this perspective,
this chapter discusses a brief introduction to the synthesis, characterization,
and structural features of different sizes of pillarenes. The presence of a
confined hydrophobic and π-electron-rich cavity provided by a paraxyl ether or hydroquinone
units offers a unique host-guest recognition capability towards positively charged
and neutral molecules. Notably, the presence of a cavity with an aromatic wall provides
a broad luminescent platform for various photophysical studies. This chapter elaborates
on the contribution of pillarenes in tuning the photophysical properties of the
small guest molecules and the formation of luminescent supramolecular
materials. Further, the functionalization on the outer of the pillarenes has influenced
the photophysical responses such as absorption and fluorescence, which paved a
pathway for the development of supramolecular organic light-emitting functional
material and novel sensor materials also discussed in this chapter. Finally,
this chapter discusses all
the progress and applications of luminescence pillarenes and their derivatives.
Keywords: Host, Host-Guest Chemistry, Luminescent materials, Pillararenes, Stimuli-Responsive.
